British 23rd Middlesex (Inns of Court) Rifle Volunteers Corps

The 23rd Middlesex Rifle Volunteers Corps was a body of men raised from the legal fraternity of the Inns of Court, Holborn, London. As a wealthier and therefore bigger Corps, for wargaming purposes it is modelled as comprising of two battalion-size units of 12 figures each. As civilians in uniform they are played as untested in combat though they are generally considered to be good shots. 

The first unit, with officer and bugler:

The second unit, lead by the Sergeant:

And examples in close up:

The custom Rifle Volunteer casts were modified to remove the cap plume and light infantry badge, replacing with a pompom and a circular badge. The reference image represents 1860 but by 1875 various Volunteer Corps seem to have been wearing a medium height shako, which is reflected in the taller headwear that has been portrayed. Despite the lack of direct evidence, a central pom-pom* has been carried over from the 1860s to the 1870s, as it helps to distinguish the units on the wargaming tabletop. The officer - as befitting wealthier volunteers - has a heavily braided coat though this is in reality a best guess as the reference image isn’t a unit-specific source. 

*Some precedent exists for the shako with central pom-pom, inasmuch as, historically, the Chelsea Pensioners of The Royal Hospital have worn a medium height version, though their current headgear is shorter:

The Officer is converted from a plastic Perry Zulu War figure in Patrol Jacket while one of the custom casts has been converted into a bugler.

The uniform colours have been painted up a little darker than in the primary reference image above.  This reflects that some artwork suggests that similar Middlesex Volunteer units wore a darker shade of grey than is shown in the aforementioned picture (see reference image below). Use of the darker grey will also help distinguish this unit from another that is to be modelled with a lighter grey uniform.